Overview

In North America, the Athena Impact Estimator for Buildings is the only free software tool that is designed to evaluate whole buildings and assemblies based on internationally recognized life cycle assessment (LCA) methodology.

Using the Impact Estimator, architects, engineers and others can easily assess and compare the environmental implications of industrial, institutional, commercial and residential designs — both for new buildings and major renovations. Where relevant, the software also distinguishes between owner-occupied and rental facilities.

The Impact Estimator puts the environment on equal footing with other more traditional design criteria at the conceptual stage of a project. It is capable of modeling 95% of the building stock in North America, using the best available data.

With Athena's proven LCA tools, determining the environmental impact of your project is no longer a guess. It's a certainty. To read the Athena LCA Tools brochure, click here.

Although the Impact Estimator doesn’t include an operating energy simulation capability, it does allow users to enter the results of a simulation in order to compute the fuel cycle burdens, including pre-combustion effects, and factors them into the overall results.

Complex Results in a User-friendly Format

Although LCA is a complex process, the Estimator has been designed for ease of use.

The first step is to enter required information such as geographic location (the user selects the most representative North American city), building life and whether it’s owner occupied or a rental property (this affects maintenance and replacement schedules), and, if desired, annual operating energy values by energy form.

Pre-set dialogue boxes prompt users to describe the different assemblies — by requesting the width, span and live load of a floor assembly, for example — that together form a conceptual building design.

Note that the first six impact measures listed above are based on mid-point impact estimation methods developed by the US EPA and reported in their Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI, 2012 version).

Simplified Tracking

As design data is entered for each assembly, the software builds a “tree” of information so that each individual assembly can be identified and viewed easily. The tree can also display, as a value or percentage, the impact of each assembly in terms of a selected measure such as global warming potential. This allows users to track the effects of each assembly as it’s added, or to quickly pinpoint what is causing a particular environmental effect.

Detailed LCA Results

Results from an individual design can be seen in summary tables and graphs by assembly group and life cycle stage. Detailed tables and graphs show individual energy use by type or form of energy, and emissions by individual substance.

Flexible Comparison of Alternate

Accommodating multiple comparisons at once, the Impact Estimator allows users to change the design, substitute materials, and make side-by-side comparisons for any one or all of the environmental impact indicators. It also lets users compare similar projects with different floor areas on a unit floor area basis.

"End of Life" (Demolition) Module

The "End of Life" module simulates demolition energy and final disposition of the materials incorporated in a building. The whole area of solid waste is in flux. Until a consensus within North America is reached in the area of solid waste, the Impact Estimator for Buildings will continue to calculate the materials and energy consumed during the "End of Life" life cycle stage and will report the total physical amount of material that actually goes to landfill as "Solid Waste to Landfill".

Structural materials have a demolition energy per physical unit of material associated with them. All materials have a percentage that goes to landfill associated with them. The location (city) has an average distance to landfill associated with it. These values are used in conjunction with the amount of material in the building at the end of life to calculate the following:

the material and energy used to demolish all structural material

the physical amount of material that is destined for landfill. Note that this is reported as the "Solid Waste to Landfill" land emission and represents the total material mass that is destined for landfill.

the material and energy used to transport to landfill the material that is destined for landfill. Note that all remaining material is assumed at this time to remain on site, pending a North American consensus.

How it works: Software User Guide

For more detailed information, please see the User Guide document, which explains what the software does and how it does it. The software’s embedded databases are also explained, highlighting their use within the tool.

System Requirements

The Impact Estimator is a Visual C# (C-Sharp) application. It is PC-compatible but can also be run on a Mac system with appropriate Windows capability.

Mac users can now log on to the Athena server and run the software remotely. This turns the user’s Mac into an interface with the Athena system, providing seamless access to the Impact Estimator. This service is available at no cost. Click here to learn more.

Highlights of Version 5

Version 5 includes the following enhancements and updates:

New green roof components available in roof envelope choices

New insulated metal panel options for both roofing materials and wall claddings

New concrete block size options available in extra basic materials

New location – Portland, Oregon – selectable from among 17 North American locations/regions

New tables and graphs reporting in accordance with the latest whole building LCA standards

New Green Globes and LEED v4 project level and comparison reports

New Bill of Materials by Assembly Group report

Updated wide flange section beam algorithms

Updated purchased electricity profiles on a regional, national and North American inter-tie level

Updated transportation by truck profiles

Note: The Impact Estimator is not an engineering design tool. It is a tool that allows users to express a design in simple terms in order to assess the environmental implications of their choices.